Yieldably mounted abrasive elements



Jan. 5, 1937 H. P. KIRCHNER .YIELDABLY MOUNTED ABRASIVE ELEMENTS FildMay 22, 1954 2 sheets -sheet 1 INVENTOR. Y P KIRGHNER ATTORNEY.

Jan. 5, 1937. H. P. KIRCHNER 2,067,089

YIELDABLY MOUNTED ABRASIVE ELEMENTS Filed May 22, 1934 2 Sheets-Sheet 2gutgiui INVENTOR. HENRY F? KRGHNER ATTORNEY.

Patented Jan. 5, 1937 UNITED STATES YIELDABLY MOUNTED ABRASIVE' ELEMENTSHenry P. Kirchner, Niagara Falls, N. Y., assignor, by mesne assignments,to The Carborundum Company, Niagara Falls, N. Y a corporation ofDelaware 8 Claims.

plurality of extended abrasive edges and a plurality of abrasivesurfaces which extend over large areas.

My improved device is illustrated by the accompanying drawings in which:

Figure 1 is a side elevation of a belt and abrasive carriers with someabrasive elements or blocks in position thereon, the fastening meansbeing only slightly indicated;

Figure 2 is an enlarged transverse section taken on the line IIII ofFigure 1 and showing fastening means for the abrasive carriers in moredetail;

Figure 3 is a transverse section of a modified abrasive block andmounting taken in a plane at right angles to that of Figure 2 andshowing a more extended base than is shown in Figure 1;

Figure 5 is a plan view of abrasive carrier showing means for attachingthe carrier to a belt at the center of the carrier as well as at theends; 1

Figure 6 is an end view of a modified form of carrier and abrasiveelement in which the element is cemented in the carrier;

Figure '7 is a side view of a portion of an abrasive belt in which theflexible support is .made up of leather links;

Figure 8 is a plan view of a portion of the abrasive belt shown inFigure the view being directed toward the working surfaces of the 5abrasive elements;

Figure 8A is a view of the opposite side of the abrasive belt shown inFigure 8, the view being directed toward the surfaces of the links whichcontact periodically with the driving pulleys;

Figure 9 is a. plan view illustrating possible arrangements of abrasiveelements on a supporting belt;

Figure 10 is a plan view of still another form of abrasive carrier andattached element;

5 Figure 11 is a side view of the carrier and Application May 2 2, 1934,Serial No. 726,960

abrasive element indicated in Figure 10, the method of attachment to thebelt being also shown;

Figure 12 is a transverse section of the element and carrier .on theline XIIXII of Fi ure 10;

Figure 13 is a fragmentary side elevation of an abrasive or polishingwheel in which the abrasive carriers and associated abrasive elementsare attached to a hub in a manner similar to the belt attachment shownin Figure 7; I

Figure 14 is a fragmentary side view of a modified abrasive wheel inwhich the carriers and associated abrasive pieces are set in slots in' awheel hub and are yieldably held against centrifugal displacement;

Figure 15 is a. section on the line XV-XV of Figure 14;

Figure 16 is a fragmentary side elevation of still another modifiedabrasive wheel in which the abrasive elements and their carriers areyieldably held on a felt rim which is carried by a rotary hub; and aFigure 17 is a section on the line XVIIXVII of Figure 16.

Referring to the drawings in detail, there is shown in Figure 1 a belt 2which may be made of canvas, leather or fiber. The belt shown in Figure1 is mounted on pulleys 3, 3. One of these pulleys may constitute thedriving pulley and the other the driven pulley. Means not shown can alsobe used for moving the pulleys further apart or closer together to varythe tension of the belt. On the belt 2 are mounted a number of similarabrasive elements 4. The abrasive elements 4 are supported in metalholders or carriers 5. These members 5 can be formed from sheet metal bystamping and pressing into channel form with extensions for fastening tothe belt as required.

In Figure 1 the upper edges of the carriers are shown as turned inwardlyto give the carrier a better grip on the abrasive element. The abrasiveelements can be slipped into or out of the carriers through the ends ofthe channels. They are therefore renewable. As shown in Figure 2, 1ugsare provided by means of which the holders F are extended longitudinallywith respect to the abrasive elements. Bolts 1 and nuts 8 are used tofasten the lugs 6 (and consequently the abrasive elements) to the belt.The pulley rim is made narrower than the belt so that the rim does notcontact with the heads of the bolts 1 or the heads are sunk in the beltto avoid jarring contacts with the pulley rim hold the abrasive memberin the holder.

- just mentioned, shellac may be used. This is cured at a temperature ofabout 350 F.

The abrasive member can be made with a broadened base as shown in Figure3, the acute lower edges helping to anchor the abrasive member in thecarrier which is shaped to resistoutward movement of the abrasivemember. The base of the carrier 9 is curved to assist the passage of thecarriers, and the abrasive elements which they support around thecylindrical sur- ,faces of the pulleys. When the abrasive elements 4'have become worn down the edges of the carrier l0 can be pried outwardlysufliciently to permit the removal of the worn element 4' and itsreplacement by a new one.

The abrasive carrier may be bolted or riveted to the flexible support atthe center of the carrier or at other convenient points along thecarrier base as indicated in Figure 5.

In the modification .illustrated in Figure 7, leather links I3 aremounted on rods l4. These rods are threaded at one or both ends and nutsl5 are used to hold the assembly of leather links together. The abrasivecarriers I6 are rotatable on the rods Id. In actual practice theabrasive elements come closer together than is indicated in Figure '7and support each other at times by lateral contact. When an abrasiveelement H has become worn down (and if it is desired to replace suchworn element) the clamping edges of the carrier l6 can be priedoutwardly to permit removal of the worn element l1 and its replacementby a new element. The leather links are somewhat resilient or flexiblein character and give a certain amount of resilience. It will be notedthat in this modification each abrasive element is flexibly mounted- Endclamps 18 can be used to hold the abrasive elements I"! againstlongitudinal movement in their carriers l6.

Instead 'of attaching the abrasive carriers to the belt at the edges ofthe belt, the carriers can be fastened (by methods described above) atpoints removed from the edges. Abrasive elements can thus be distributedin various patterns over the face of the belt as indicateddiagrammatically in Figure 9. The abrasive elements are shown in thisview in staggered relationship to avoid as much as possible streak markson the work. The arrangement oi'the abrasive members is such thatthelonger abrasive edges act princi-, pally on thework. The longchannels make it comparatively easy to dispose oi! debris.

In the forms of abrasive carrier indicated in Figures 10, 11 and 12, theabrasive element 2| is cemented as at 21 in a metal holder 22. Thisholder has side flaps 23 and end flaps 24 which can be pried loose fromthe sides and endsoi the abrasive element when it is desired to renewthe latter, the residue of the abrasive material being chiselled fromthe base. The holder or carrier can be attached to the belt by means ofbolts and nuts as indicated at 25. A screw may be acevpsa used to holdthe central portion of the carrier to the belt as indicated at 26.

In Figure 13 there is shown a form of abrasive or polishing wheel inwhich the grinding or polishing elements 3| are mounted in carriers 32which are adapted to oscillate on rods 33 which are in turn supp rted inthe hub 34. The abrasive elements 3| are supported in their carriers 32in a manner similar to that shown for the abrasive elements indicated inFigure 7. Such an abrasive wheel is adapted to the grinding or polishingof certain types of uneven surfaces and has certain advantages over arigid abrasive wheel. One of the particular advantages lies in the factthat a worn abrasive element can be easily renewedp In the modificationshown in Figures 14 and 15 the abrasive elements are also easilyrenewed. The abrasive carriers 42 are set in recesses 43 of a rotaryvhub. The abrasive carriers are provided with terminal hooks 44. Anendless resilient member 45 (consisting for example of a continuoushelical spring) is supported on the hooks 44 and resists the tendency ofthe abrasive element to move outwardly when the wheel is in rotation.

In the modification shown in Figures 16 and 1'7, the abrasive carriers52 are supported on a felt rim 53 which in turn is supported on theperipheral surface of a rotary hub. Resilient members 55 are used tohold the abrasive carriers 52 against the felt rim 53 in a mannersimilar to that described for the extensible members 45 shown in Figures14 and 15. The felt rim gives a softer grinding action than is obtainedwhen the abrasive carriers are supported on a rigid surface.

The abrasive members can be made in large numbers by means ofbriquetting machines, using standard abrasive mixes containing abrasivegrain and a bond that can be hardened by one or more of the usualmethods, for example by heating. For rapid grinding of metal surfaces,silicon carbide or fused aluminous grain of comparatively large gritsize is desirable. As compared with grinding operations by means ofabrasive wheels a number of diiferences'are to be noted. Thesedifierences affect the character of the bond to be used for the abrasivegrain. In the applicant's apparatus the abrasiveeffects depend more onimpact action than is the case with abrasive wheels. In the applicantsPDa-mtus, the leading edges oLthe abrasive members sustain repeatedshocks by successive contacts where the travelling belt is passing overa rough surface. Hence a tough bond suchas shellac has some advantagesover a clay or glass bond, since a clay or glass bond is more brittle.

As compared with the usual form of sanding belt my abrasive belt allowsmuch more clearance for debris donned by material removed from the workand from the grinding device. Abrasive elements are easily replacedsince they can be supplied already mounted in their metal carriers andattached to the belt by bolting or by other simple clamping means.

As has been suggested above, many different kinds of abrasive grain maybe used in tomiing of abrasive carriers each of which is rotatablymounted on a single one of said rods, and rigid abrasive elementsclamped in said carriers, each element being held at a constant distancefrom the rod that supports its carrier.

2. An abrasive device comprising an endless belt composed of links whichare mounted for relative movement on parallel rods, a plurality ofabrasive carriers each of which is rotatably mounted on a single one ofsaid rods,,and rigid abrasive elements clamped in said carriers, each ofsaid-links being'composed of a flexible material, I

3. A flexible abrasive article adapted to be driven by a pair ofcylindrical pulleys mounted on parallel shafts, said flexible abrasivearticle comprising an endless belt containing parallel rows of links oflight strong material, transverse rods in said belt each of which passesthrough a link in each row, consecutive parallel rods being connected bylinks in alternate rows, a plurality of abrasive carriers each mountedfor limited oscillation on one of said rods, and a rigid abrasive blockclamped in each of said carriers.

4 A flexible abrasive article adapted to be driven by a pair ofcylindrical pulleys mounted on parallel shafts, said flexible abrasivearticle comprising an endless belt containing parallel rows of leatherlinks, transverse rods in said belt each of which passes through a linkin each row in a direction parallel to the driving shafts, consecutiveparallel rods being connected by links in alternate rows, a plurality ofabrasive carriers each mounted for limited oscillation on one of saidrods, and a rigid abrasive block clamped in each of said carriers byclamping means which contact with the sides of said block adjacent itsbase.

5. A flexible abrasive article adapted to be driven, by a pair ofcylindrical pulleys mounted on parallel shafts, said article comprisinga belt containing a series of rows of links of light strong material,each of said links having a high coefficient of friction on. its edgesand the links in any one row being offset a half link with respect tothe links of an adjacent row, a series of transverse metal rods in saidbelt for interconnecting a plurality of links, an abrasive carrierrotatably mounted on each rod, and an abrasive block mounted in each ofsaid carriers, said blocks being similar in shape and presenting outersurfaces which are approximately parallel to the direction of motion ofthe adjacent portion of the linked belt.

6. An endless abrasive belt comprising a plurality of rows of linksarranged in parallel planes, each row contacting with the same drivingpulley and the same driven pulley, a plurality.

of transverse rods each of which passes loosely through a terminalportion of a link in each row but through oppositely extending links inthe 'case of adjacent rows, and a bar of bonded abrasive mounted foroscillatory movement about each rod as well as for continuous movementwith the belt.

7. A flexible abrasive device comprising an endless belt composed oflinks which are mounted in a plurality of parallel rows for successivemotion by engagement with a pair of pulley wheels, a plurality ofabrasive carriers each mounted for limited movement on a rotarysupportthat passes transversely through a plurality of said links, and a rigidabrasive element 7 clamped in each bf said carriers.

8. A flexible abrasive device comprising an endless belt containinglinks which are mounted in a plurality of parallel rows for successivemovement by engagement with a pair of pulley wheels, aplurality ofabrasive carriers extending transversely of the belt outside of saidlinks, each of the carriers being mounted on a rotary support thatpasses transversely through a plurality of said links, and a rigidabrasive element. mounted in each of said abrasive carriers, theabrasive elements having bases of larger area than the outermostgrinding surfaces whereby an abrasive element can be retained againstoutward movement by flanges on its carrier which converge toward theworking surface of the abrasive element.

may P. KIRCHNER.

